The present invention relates to a printed board arranged with a plurality of printed wires which transmit a driving voltage from a drive IC to a plurality of individual terminals which are provided on a piezoelectric element of an ink jet printer in correspondence to ink discharge ports, and are applied with the driving voltage when generating pressure to discharge the ink, and also relates to an ink jet head equipped with the printed board.
In the ink jet printer, color printing is performed using a plurality of ink cartridges such as cyan, magenta, yellow, black and the like. The ink supplied from a plurality of ink cartridges is discharged from a plurality of discharge ports formed in the ink jet head by the pressure generated by the piezoelectric element.
The piezoelectric element includes a plurality of individual terminals, in correspondence to the plurality of ink discharge ports, to be applied with the driving voltage, and driving voltage is supplied from the drive IC to each individual terminal via the flexible printed board connected to the piezoelectric element. There are advantages that the degree of freedom of mounting when mounting the ink jet head to the ink jet printer can be increased and that the ink jet printer can be miniaturized by using the flexible printed board for the transmission of the driving voltage, control signal and the like. In recent years, COF (Chip On Film) in which the drive IC is directly mounted on the flexible printed board is put to practical use, COF thus allows the distance from the drive IC to the piezoelectric element to be shorter, thereby reducing attenuation, delay and the like of the driving voltage and efficiently driving the piezoelectric element.
In the connecting configuration of the flexible printed board disclosed in Japanese Patent Application Laid-Open No. 2004-114609, columns of a plurality of terminal lands are arranged adjacent to each other in a zigzag manner on a band shaped insulating body, and through holes are formed in the insulating body in correspondence to the arrangement position of the terminal lands. Each terminal land is thus exposed from the opposite surface of the insulating body, and connected to the terminal of the piezoelectric element by arranging a solder on the exposed terminal land. The plurality of terminal lands are arranged at high density by arranging the columns of the terminal lands adjacent to each other in a zigzag manner. Further, the printed wire from the drive IC to the terminal land is passed between the terminal lands, led to the corresponding terminal land, and connected to each terminal land so as to avoid the other terminal lands.